TY - GEN
T1 - Nucleation of c-axis screw dislocations at substrate surface damage during 4H-Silicon carbide homo-epitaxy
AU - Dudley, M.
AU - Zhang, N.
AU - Zhang, Y.
AU - Raghothamachar, B.
AU - Sanchez, E. K.
PY - 2010
Y1 - 2010
N2 - Observations of dislocation nucleation occurring at substrate surface scratches during 4H-SiC CVD homoepitaxial growth are reported. Sub-surface residual damage associated with the scratches is observed to act as nucleation sites for basal plane dislocations (BPDs), threading edge dislocations (TEDs) and threading screw dislocations (TSDs) in the epilayer. TEDs and BPDs replicate from the surface intersections of basal plane dislocation half-loops injected into the substrate surface. A model for the nucleation mechanism of TSDs, which nucleate in opposite sign pairs, is presented which involves overgrowth of surface indentations associated with the scratch during step flow growth. Atomic steps which approach these local surface indentations can collapse creating pairs of opposite sign screw dislocations which have Burgers vector magnitude equal to the magnitude of the step disregistry created during the collapse.
AB - Observations of dislocation nucleation occurring at substrate surface scratches during 4H-SiC CVD homoepitaxial growth are reported. Sub-surface residual damage associated with the scratches is observed to act as nucleation sites for basal plane dislocations (BPDs), threading edge dislocations (TEDs) and threading screw dislocations (TSDs) in the epilayer. TEDs and BPDs replicate from the surface intersections of basal plane dislocation half-loops injected into the substrate surface. A model for the nucleation mechanism of TSDs, which nucleate in opposite sign pairs, is presented which involves overgrowth of surface indentations associated with the scratch during step flow growth. Atomic steps which approach these local surface indentations can collapse creating pairs of opposite sign screw dislocations which have Burgers vector magnitude equal to the magnitude of the step disregistry created during the collapse.
KW - Atomic step disregistry
KW - Sub-surface damage
KW - Substrate surface scratch
KW - Threading edge dislocation
KW - Threading screw dislocation
UR - https://www.scopus.com/pages/publications/77955464054
U2 - 10.4028/www.scientific.net/MSF.645-648.295
DO - 10.4028/www.scientific.net/MSF.645-648.295
M3 - Conference contribution
SN - 0878492798
SN - 9780878492794
T3 - Materials Science Forum
SP - 295
EP - 298
BT - Silicon Carbide and Related Materials 2009
PB - Trans Tech Publications Ltd
T2 - 13th International Conference on Silicon Carbide and Related Materials 2009, ICSCRM 2009
Y2 - 11 October 2009 through 16 October 2009
ER -